For pay-as-you-go cell phone users, using high-end smartphones can be a pricey investment. Vodafone, a UK cell phone service, has a nifty solution to the cost problem that also happens to be great for the planet: pre-used smartphones. The Vodafone Nearly New program repackages gently used smartphones and sells them along with a pay-as-you-go or contract plan at a fraction of the normal cost.

The Nearly New program is an expansion on the existing refurbished phone market, allowing pay-as-you-go customers the option to use a smartphone that may not have been previously available on a PAYG plan. The program is an attempt to lure in additional smartphone users because, while voice and SMS usage has stagnated, data usage in the phone market is still growing.

Vodafone’s inventory will vary from month to month depending on the type of phone that is in stock and each phone is guaranteed for 12 or 24-months depending on the plan — a detail that sets it apart from simply purchasing a used phone on eBay or Craigslist. Currently, an iPhone 4, the latest iPhone available through the program, runs about $400 using the PAYG plan. If you opt for the monthly plan, a smartphone like the Samsung Galaxy S III is free.